All terrain vehicle

ABSTRACT

Various embodiments of a saddle type vehicle are described. Configurations are shown in which the engine is located more towards the rear of the vehicle and in which the fuel tank extends generally vertically beneath the steering member. A radiator may also be located at a rear portion of the vehicle, rearwardly of the engine. A front storage compartment is also provided in the front portion of the vehicle. The resulting vehicle has improved access and storage capabilities and also has a lower center of gravity.

FIELD OF THE INVENTION

[0001] The present invention relates to the field of all terrainvehicles. More particularly, the invention relates to a saddle typevehicle comprising improved features.

BACKGROUND TO THE INVENTION

[0002] During the last decade or so, the popularity of all terrainvehicles (also referred to as “ATV's”) has greatly increased. Thesetypes of vehicles are indeed very practical and versatile as they may beused for work or leisure related tasks. By virtue of their relativelycompact nature, their great mobility and traction, they are capable ofcirculating in all sorts of surfaces, from the common back yard to themore challenging wood trail. Since they are also fairly powerful, allterrain vehicles are also used to pull or push various objects such as atrailer or a snow-plow.

[0003] Initially, these types of vehicle comprised a steerable frontwheel and two driving rear wheels connected to an engine. Suchthree-wheeled vehicles were however very unstable and had a tendency tooverturn and cause serious injuries, if not death, to the user. In orderto increase stability, the three-wheel base was therefore changed to afour-wheel base.

[0004]FIG. 1 illustrates an embodiment of a saddle-type vehicletypically found in the prior art. Such a vehicle comprises four wheelsmounted to a frame, the front ones being steerable. A fuel tank and aseat are disposed on an upper portion of the frame. The engine, whichrepresents one of the heaviest components of the vehicle, is typicallymounted in a central portion of the vehicle, usually below the fuel tankand a front portion of the seat. The engine location is specificallychosen to ensure a proper weight distribution. If the engine is watercooled, a radiator will be provided in front of the engine. Examples ofsuch vehicles are described in more details in U.S. Pat. No. 4,757,872,issued on Jul. 19, 1988 and naming Inomata as inventor and in U.S. Pat.No. 5,515,940, issued on May 14, 1996 and naming Shichinohe et al. asinventors.

[0005] While such a configuration provides vehicles with performancelevels that are more than adequate, there are nonetheless manydisadvantages associated with it.

[0006] In order to sit properly and drive astride, the user must “mount”the vehicle, i.e. he or she must raise one leg over the fuel tank, seator rear portion of the vehicle in order to sit on or get off thevehicle. Thus, one of the main disadvantages is that access to and fromthe vehicle can be somewhat challenging. Because of this, some personstend to drive while assuming a “side-saddle” position and changing gearsusing a rope tied to the gear lever. This is impractical.

[0007] Another inconvenience associated with the location of the fueltank is that it renders engine access more difficult since there islittle space between the cylinder head of the engine and the tank. Thisis impractical during repair since the fuel tank must be removed. Sincethe fuel tank is also a relatively heavy component and since it islocated on the upper portion of the frame, the above-mentionedconfiguration also has the disadvantage of creating a relatively highcenter of gravity.

[0008] The location of the radiator in front of the engine also hasvarious disadvantages. Since, during normal use, the vehicle travelsmostly in the forward direction, the front-located radiator is moreexposed to the possibility of being pierced by a branch or the like orbeing obstructed by mud. In order to compensate for this, it may bepossible to cover the radiator with a protective member but this reducesthe amount of air reaching the radiator thereby reducing its coolingefficiency. This location of the radiator is also an ineffective use ofvaluable space.

[0009] The configuration referred to above also leaves very little roomto accommodate storage compartments or additional accessories,especially in the front portion of the vehicle.

OBJECTS AND SUMMARY OF THE INVENTION

[0010] It is therefore an object of the present invention to provide asaddle-type vehicle having an improved frame and improved accessfeatures.

[0011] It is a further object of the present invention to provide asaddle-type vehicle having a relatively lower center of gravity.

[0012] It is yet another object of the present invention to provide avehicle having improved storage capabilities.

[0013] As embodied and broadly described herein, the invention providesa saddle-type vehicle comprising a frame, a pair of front wheelssuspended from a front portion of the frame, a pair of rear wheelssuspended from a rear portion of the frame, a power unit mounted on theframe, a transmission allowing the power unit to transmit power toeither one of the front or rear pairs of wheels, a seat located inbetween the front and rear pairs of wheels, wherein a main portion ofthe power unit is disposed beneath the seat.

[0014] In a preferred embodiment, a main portion of the transmission isalso disposed beneath the seat and the power unit comprises a crankshaftand a transmission shaft extending in a running direction of thevehicle, and a rear drive shaft is connected to a rear end of thetransmission shaft on one end and to a rear differential on the otherend to allow the power unit to transmit power to the pair of rearwheels.

[0015] In the context of the present specification, the term“differential” should be interpreted as meaning any types of device thatis capable of imparting a rotational movement to a pair of wheels from adriving shaft, whether or not it permits one wheel to revolve fasterthan the other one. This includes any type of gearing such as ring andpinion gearing, spiral gearing, hypoid gearing, worm gearing or thelike. This also includes any types of viscous coupling.

[0016] In another preferred embodiment, the vehicle comprises a frontdrive shaft connected to a front end of the transmission shaft on oneend and to a front differential on the other end to allow the power unitto transmit power to the pair of front wheels.

[0017] In another embodiment, the power is transmitted to either one ofthe front or rear pairs of wheels through a drive chain and sprocketarrangement.

[0018] In a preferred variant, the seat is pivotal connected to theframe, the seat being moveable between a first position whereby thedriver may drive the vehicle and a second position whereby the drivermay access the power unit. The seat preferably comprises a pommellocated at a front portion thereof and is most preferably removablyconnected to the frame.

[0019] As embodied and broadly described herein, the invention alsoprovides a saddle-type vehicle comprising a frame, a pair of frontwheels comprising first and second wheels suspended from a front portionof the frame, a pair of rear wheels comprising third and fourth wheelssuspended from a rear portion of the frame, the first and second wheelsdefining a first transversal axis and the third and fourth wheelsdefining a second transversal axis, a power unit mounted on the frame, atransmission allowing the power unit to transmit power to either one ofthe front or rear pairs of wheels, a seat located in between the frontand rear pairs of wheels, wherein a main portion of the power unit islocated between the second transversal axis and an imaginary axislocated at a median point between the first and second transversal axis.

[0020] In a preferred embodiment, the power unit comprises a crankshaftand a transmission shaft extending in a running direction of thevehicle, and wherein a rear drive shaft is connected to a rear end ofthe transmission shaft on one end and to a rear differential on theother end to allow the power unit to transmit power to the pair of rearwheels. Most preferably, the vehicle also comprises a front drive shaftconnected to a front end of the transmission shaft on one end and to afront differential on the other end to allow the power unit to transmitpower to the pair of front wheels.

[0021] In yet another aspect, the invention provides a saddle-typevehicle comprising a frame, a pair of front wheels suspended from afront portion of the frame, a pair of rear wheels suspended from a rearportion of the frame, a power unit mounted on the frame, a fuel tank, atransmission allowing the power unit to transmit power to either one ofthe front or rear pairs of wheels, a seat located in between the frontand rear pairs of wheels, wherein a main portion of the fuel tank isdisposed substantially below the horizontal plane defined by theuppermost portion of the seat. Preferably a main portion of the powerunit and of the transmission are disposed beneath the seat.

[0022] As embodied and broadly described herein, the invention furtherprovides a saddle-type vehicle comprising a frame, a pair of frontwheels suspended from a front portion of the frame, a pair of rearwheels suspended from a rear portion of the frame, a steering memberconnected to a steering mechanism for steering the front wheels, a powerunit mounted on the frame, a fuel tank, a transmission allowing thepower unit to transmit power to either one of the front or rear pairs ofwheels, a seat located in between the front and rear pairs of wheels,wherein a main portion of the fuel tank is located beneath the steeringmember. Preferably, a main portion of the fuel tank is also disposedsubstantially below the horizontal plane defined by the uppermostportion of said seat and is disposed vertically.

[0023] In a further aspect, the invention also provides a saddle-typevehicle comprising a frame, a pair of front wheels suspended from afront portion of the frame, a pair of rear wheels suspended from a rearportion of the frame, a steering member connected to a steeringmechanism for steering the front wheels, a seat located in between thefront and rear pairs of wheels, a power unit mounted on the frame andhaving a main portion thereof being disposed beneath the seat, a fueltank located beneath the steering member, a transmission allowing thepower unit to transmit power to either one of the front or rear pairs ofwheels, the vehicle further comprising an open area located between thefuel tank and the power unit, the open area providing easier access toand from the vehicle. The vehicle may comprise an additional storagecontainer removably secured in the open area and the additional storagecontainer may be an additional fuel tank.

[0024] As embodied and broadly described herein, the invention providesa saddle-type vehicle comprising a frame, a pair of front wheelscomprising first and second wheels suspended from a front portion of theframe, a pair of rear wheels comprising third and fourth wheelssuspended from a rear portion of the frame, a water cooled enginemounted on the frame, a transmission allowing the engine to transmitpower to either one of the front or rear pairs of wheels, a seat locatedin between the front and rear pairs of wheels, the vehicle furthercomprising a radiator located at the rear portion of the frame.

[0025] Preferably, the radiator is located between the third and fourthwheels, behind the seat and is angled generally toward the seat.

[0026] In a preferred embodiment, the radiator further comprises acooling fan disposed behind the radiator and the vehicle also comprisesa ventilation opening for conveying cooling air to the radiator. Mostpreferably, the vehicle comprises at least two ventilation openingslocated above the third and fourth wheels respectively.

[0027] In another aspect of this invention, there is provided asaddle-type vehicle comprising a frame, a pair of front wheels suspendedfrom a front portion of the frame, a pair of rear wheels suspended froma rear portion of the frame, a steering member connected to a steeringmechanism for steering the front wheels, a seat located in between thefront and rear pairs of wheels, a power unit mounted on the frame, afuel tank, a transmission allowing the power unit to transmit power toeither one of the front or rear pairs of wheels, the vehicle furthercomprising a storage compartment located forward of the steering member.

[0028] The invention also provides a saddle-type vehicle comprising aframe, a pair of front wheels suspended from a front portion of theframe, a pair of rear wheels suspended from a rear portion of the frame,a steering member connected to a steering mechanism for steering thefront wheels, a seat located in between the front and rear pairs ofwheels, a power unit mounted on the frame and having a main portionthereof being disposed beneath the seat, a fuel tank located beneath thesteering member, a transmission allowing the power unit to transmitpower to either one of the front or rear pairs of wheels, the vehiclefurther comprising an open area located between the fuel tank and thepower unit, the open area providing easier access to and from thevehicle, the vehicle further comprising a storage compartment locatedforward of the steering member.

[0029] The saddle-type vehicle of the present invention offers manyadvantages over the prior art. By moving the engine rearwardly and bypreferably moving the fuel tank forward and downwardly, there isprovided a saddle-type vehicle having a open area that allows easieraccess to the vehicle. This also provides the user with the option ofmaximizing this area by adding an additional storage container, such asa additional fuel tank. The resulting vehicle also has a lower center ofgravity.

[0030] The improved radiator location also reduces the probabilities ofit being damaged while freeing an important amount of space in the frontportion of the vehicle that may be used an additional larger storagearea.

[0031] Other objects and features of the invention will become apparentby reference to the following specification and to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The following is a description by way of a preferred embodiment,reference being made to the following drawings, in which:

[0033]FIG. 1 is a side view of a saddle-type vehicle according to theprior art;

[0034]FIG. 2 is a perspective view of a saddle-type vehicle according tothe present invention;

[0035]FIG. 3 is a side view of a vehicle according to the presentinvention illustrating more particularly the frame and the powertransmission system;

[0036]FIG. 4 is a perspective view of a frame;

[0037]FIG. 4a is a side view of a frame;

[0038]FIG. 5 is a top plan view of a vehicle according to the presentinvention illustrating more particularly the frame and the powertransmission system;

[0039]FIG. 6 is a top plan view of a vehicle according to the presentinvention;

[0040]FIG. 7 is a side view of the vehicle illustrated in FIG. 2;

[0041]FIG. 8 is a side view illustrating the front hatch in an openposition and the seat in an engine access position;

[0042]FIG. 9 is a perspective view of a seat and mounting bracketsthereof;

[0043]FIG. 10 is a perspective view of a rear portion of a vehicleaccording to the present invention illustrating the position of theradiator;

[0044]FIG. 11 is a perspective view of a portion of a seat and rearfenders illustrating the ventilation openings;

[0045]FIG. 12 is an exploded view of the rear fenders and ventilationchannels cover;

[0046]FIG. 13 is a perspective view of a front storage compartment withthe hatch in an open position;

[0047]FIG. 14 is a perspective partial view of the steering member,instrumentation panel and fuel tank;

[0048]FIG. 15 is a perspective view of an additional storage container;

[0049]FIGS. 16 and 17 are side views of a vehicle according to thepresent invention comprising an additional container.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0050]FIG. 1 illustrates a saddle-type vehicle 2 conventionally found inthe prior art. Such a vehicle comprises four wheels 10 mounted to aframe 12, the front ones being steerable through a steering member 14connected to a steering mechanism (not shown). The frame 12 comprises anupper member 12′ extending on an upper portion of the vehicle above thepower unit and a lower member 12″ extending on a lower portion thereof.A fuel tank 16 and a seat 18 are disposed on an upper portion of theframe 12. The power unit 20, which represents one of the heaviestcomponents of the vehicle, is typically mounted in a central portion ofthe vehicle, usually below the fuel tank 16 and a front portion of theseat 18. If the power unit is a water cooled engine, a radiator will beprovided in front of the engine.

[0051] A preferred embodiment of the saddle-type vehicle according tothe present invention is generally illustrated in FIGS. 2 and 3.

[0052] Referring now to FIGS. 3 and 4, the vehicle, generally referredto at 30, comprises a main frame portion 34 and a secondary frameportion 38 that is attached to the main frame portion 34 at attachmentpoints 42 and 46 which may consist of typical brackets. The front areaof the main frame portion comprises all the attachments that arenecessary to receive and accommodate the upper and lower frontsuspension arms, the front differential, steering linkage and othertypical components including a front bumper 35. The rear area of themain frame portion extends upwardly and terminates by the two upperbrackets 46 and the two lower brackets 42. The main frame portion alsocomprises openings 41 for pivotally attaching rear swing arms asdescribed below and brackets 44 for mounting the power unit. The upperand lower brackets 46 and 42 are used to attach the secondary frameportion 38 to the main frame portion 34 as explained before. The upperbrackets 46 are also used to receive and attach the upper end of therear shock absorbers 50 to the main frame portion 34. Both the main andthe secondary frame portions are of conventional construction and may beconstructed from tubular or stamped members.

[0053] The provision of a main and of a secondary frame portions providevarious advantages. First, the inventors have realized that it may bemore efficient on an assembly line to manufacture a frame in two partsrather than as a single component when using conventional tooling. Incontrast with the vehicles of the prior art, the main frame portion ofthe vehicle of the present invention does not comprise an upper memberthat is located above the power unit (referred to at 12′ in FIG. 1) andthat prevents the frame from bending. As a result, the main frameportion of the vehicle of the present invention must be capable ofwithstanding the same amount of stress that is imparted on aconventional frame. Typically, this will be achieved by manufacturingthe main frame portion from a material having a higher creep resistenceor by using larger members. Reinforcement members, such as 36 and 7 mayalso be provided to assist the main frame portion in maintaining itsstructural integrity. Since the main frame portion is intended toaccommodate the majority of the stress imparted to the vehicle, thesecondary frame portion may as a result be manufactured using a smallerstructure or from a less expensive material. Apart from reducing costs,such an embodiment also has the advantage of providing a lightervehicle. The person skilled in the art will however realize that this isonly a preferred embodiment and that the objects of the presentinvention may be achieved using a unitary frame structure.

[0054] A pair of front wheels comprising a first wheel 58 and a secondwheel 60 is suspended from the front area of the main frame portion.More particularly, the vehicle comprises upper suspension arms 64 (FIG.5) and lower suspension arms (not shown) that are pivotally attached tothe frame at one end and to a steering knuckle via ball joints at theother end. The steering knuckles each comprise a spindle adapted toreceive a wheel and its bearings. The steering knuckles are connected toa steering member 100 through a conventional steering linkage ormechanism so as to provide steerable front wheels. A pair of front shockabsorbers/coil springs assemblies 70 connected to the frame at bracket39 at one end and to the upper suspension arms at the other end are alsoprovided.

[0055] If the vehicle is intended to be of the four wheel drive type,power is transmitted from the power unit to the front wheels through aconventional mechanism comprising front axles 68 and a frontdifferential 72 that is coupled to the power unit via a front drivingshaft 76.

[0056] A pair of rear wheels comprising a third wheel 80 and a fourthwheel 82 is suspended from the rear area of the main frame portion. Moreparticularly, the vehicle comprises rear swing arms 84 that arepivotally connected to the main frame portion at one end and to the rearaxle casing 86 at the other end. A pair of rear shock absorbers/coilspring assemblies 50 connected to the main frame portion on one end andto the rear axle casing 86 on the other end are also provided.Alternatively, a single shock absorber/coil spring assembly could beused at the rear, provided it is located in a generally median location.

[0057] Power is transmitted from the power unit to the rear wheelsthrough a conventional mechanism comprising a rear differential 90 thatis coupled to a rear driving shaft 94 at one end and to a rear axlelocated in rear axle casing 86 at the other end. The rear driving shaftis located in a suitable housing. In a preferred embodiment, one of therear swing arms 84 may serve as a housing for the rear driving shaft. Inorder to accommodate the angular movement of the rear swing arm, auniversal joint is provided at a suitable location, preferably near thepower unit.

[0058] While the preferred embodiment has been described using driveshafts to transmit power from the power unit to the front or rear pairsof wheels, other types of power transmission means may be provided. Forexample, the drive shafts could be replaced by suitable drive chain andsprocket arrangement.

[0059] As shown more particularly in FIG. 14, an instrument board 210 isprovided on the steering member 100 and comprises the usual indicatorssuch as speedometer, odometer, indicator lights, etc. A device forelectrically shifting gears 214 may also be provided if the vehicle isequipped with a semi-automatic transmission. A main gear lever 212, forselectively engaging either one of a Park, Neutral, High, Low or Reverseposition is also conveniently located near the steering linkage.

[0060] The vehicle is also provided with a conventional brakingmechanism which may comprise disk or drum brakes. The brakes may behydraulically or mechanically activated.

[0061] As shown more particularly in FIGS. 2, 6 and 7, the vehicle alsocomprises front fenders 104 attached to the frame and defining frontwheelhouses 108. The front portion of the vehicle also comprise a frontgrille 106 and headlamps 107 and may comprise a front rack 110. A frontstorage compartment is also provided at the front portion of thevehicle, in front of the steering member 100. Rear fenders 112 are alsoattached to the frame. The rear fenders may also comprise splash guards120 and a rear rack 124. As shown more particularly in FIG. 10, the rearportion of the vehicle may also comprise reflective tapes 132 and a rearlamp 134. The rear fenders also comprise ventilation openings 130, thepurpose of which will be described hereinafter. Front and rear bumpers35 and 128 are also respectively secured to the main and secondary frameportions 34 and 38.

[0062] Full foot rests 54 are also provided on each sides of thevehicle, in between the front and rear fenders. The foot rests 54 mayaccommodate a gear shift lever (if the vehicle does not have asemi-automatic transmission) and brake lever (not shown). The provisionof full foot rests provides increased comfort in contrast with thetypical foot peg since the weight is distributed over the entire bottomsurface of the foot.

[0063] A saddle-type seat 140 is also removably secured to the frameusing generally U-shaped brackets 142 (FIGS. 8 and 9) or 143 (FIG.4)that are securely fixed to the frame. As shown in FIG. 9, the seatcomprises a base portion 146 made from a suitable material such asplastic. The base portion 146 is shaped so as to surround and enclosethe power unit thereby enhancing the aesthetics of the vehicle when theseat is in a closed position as shown in FIG. 7. The upper portion ofthe seat is provided with a suitable padding material and a pommel 141is disposed at a front portion thereof to improve comfort. A supportmember 144 is secured to the base 146 and is adapted to engage bracket142 or 143 to secure the seat in place. A locking device 148 maintainsthe seat in a closed position wherein the driver may drive the vehicle.

[0064] As shown in FIG. 8, the engine compartment of the vehicle isreadily accessible by simply pivoting and/or removing the seat. In orderto remove the seat, the user unlocks the locking device 148, pivots theseat upwardly and thereafter slides the seat rearwardly until thesupport member 144 clears the upper portions of the brackets 142 or 143.

[0065] Since the power unit is enclosed beneath the seat 140,ventilation openings 147 are preferably provided in the base portion 146of the seat in order to ensure proper ventilation of the enginecompartment. The ventilation openings 147 preferably also extend to theside of the seat since accessories, which would block the openings, maybe provided in front of the base portion of the seat as shown in FIGS.16 and 17.

[0066] A suitable type of power unit for use in the context of thepresent invention is preferably capable of simultaneously driving thefront and rear wheels, although rear wheel drive vehicles may also becontemplated. A preferred type of power unit includes an engine and atransmission integrally joined to one another. The crankshaft, main andsecondary shafts and output or transmission shaft all extend in the samedirection which preferably corresponds to the longitudinal direction ofthe vehicle. In a preferred embodiment, the transmission shaft isconnected to the rear driving shaft 94 at one end and, if the vehicle isof the four wheel drive type, is also connected to the front drivingshaft 76 at the other end. The power unit comprises all the necessarycomponents such as a carburetor 152, an exhaust pipe 154, a muffler 156,an air filter 158 having an air intake, and a battery 160.

[0067] The basic internal construction of the power unit will not bedescribed in details as it will be readily apparent to the personskilled in the art that the invention may be practiced with any suitabletypes of power units.

[0068] In contrast with the prior art, where the power unit is mountedin a central portion of the vehicle, the power unit of the vehicle ofthe present invention is mounted more towards the rear portion of thevehicle.

[0069] In a first preferred embodiment, the position of the power unitmay be defined in relation to various transversal axis. Morespecifically, the location of the power unit 150 may be defined inrelation to an imaginary axis x³ that is located at a median pointbetween a first transversal axis x¹ defined by the front wheels 58 and60 and a second transversal axis x² defined by the rear wheels 80 and82. More particularly, in this embodiment, a main portion of the powerunit is located in between the median axis x³ and the second axis x².

[0070] If, in another embodiment, the vehicle is provided with two pairsof rear wheels, for a total of six wheels, the second axis x² willdefined by the two foremost rear wheels.

[0071] In another embodiment, the location of the power unit may bedefined in relation to the seat. Thus, as shown in FIGS. 3 and 8 and incontrast with the prior art, the present invention may be characterizedby a vehicle in which a main portion of the power unit 150 is disposedbeneath the seat 140.

[0072] Another aspect of the invention resides in the location of thefuel tank 160. Since a full fuel tank represents a relatively heavycomponent of the vehicle, its location is important to ensure properweight distribution and proper balance of the vehicle. As shown in FIGS.3, 6 and 14, in one embodiment, the fuel tank, that comprises a fuel cap162 and a fuel gage 164, extends vertically beneath the steering member100 and more particularly, substantially below the horizontal plane z′defined by the uppermost portion of the seat 140.

[0073] The location of the fuel tank at this specific area provides manybenefits. First, by providing a tank that extends in the verticaldirection, it is possible to concentrate an important amount of weightin the lower portion of the vehicle thereby lowering its center ofgravity.

[0074] By moving the fuel tank 160 from an upper portion of the frame toan area located generally beneath the steering member 100, there isprovided an open area 200, between the fuel tank 160 and the power unit150. This open area 200 facilitates access to and from the vehicle asthe driver does not have to raise his leg above the level of the fueltank, seat or rear portion of the vehicle. The open area also providesspace to secure additional storage containers.

[0075] The person skilled in the art will realize that some objects ofthe present invention may be achieved by locating the fuel tank at anarea other than beneath the steering member 100. For example, the fueltank could be located at a front portion of the vehicle, and couldsurround the steering linkage. The location of the fuel tank willtherefore be dictated by balance and security considerations.

[0076] If the power unit is a water-cooled engine, the vehicle maycomprise a radiator 170. In the preferred embodiment, the radiator islocated behind the engine at the rear area of the secondary frameportion. The radiator may be fixed to the frame by securing it tobracket 47 (FIG. 4). As shown more particularly in FIG. 10, the radiatoris preferably inclined forward and upwardly towards the seat of thevehicle and comprises a grille (not shown) and a schroud 174 protectingthe grille. A cooling fan 172 is mounted within the shroud in aconventional manner.

[0077] The provision of a radiator at the rear portion providesincreased protection by limiting its exposure. Since, during normaloperation, the vehicle travels mostly in the forward direction, thepossibilities of the rearwardly located radiator being pierced by abranch or the like are therefore substantially reduced. The location ofthe radiator at the rear portion of the vehicle also permits to make amore efficient use of the space in the front portion thereof andprovides room to more efficiently locate the fuel tank as explainedabove.

[0078] Referring now to FIGS. 11 and 12, there are provided forwardfacing ventilation openings 130 for conveying air to the radiator 170.In order to convey the cooling air, ventilating channels 190 are definedwithin the rear fenders 112 as shown more particularly in FIG. 12. Acover portion 113 covers the channel and protecting grilles 192 areprovided to prevent debris from entering and blocking the ventilatingchannels.

[0079] By locating the radiator at a rear portion of the vehicle, theinventors were also capable of maximizing the amount of space at thefront of the vehicle. By providing a rear radiator, the inventors werecapable of providing a front storage compartment 180 at a front portionof the vehicle, forward of the steering member (FIG. 3). The storagecompartment comprises a hatch 184 that is pivotally secured to thevehicle and that is preferably removable. The front storage compartmentmay be provided with a waterproof removable container 185 that may beused as a cooler or that may be used as a tank to keep the catch of theday if the user is an avid fisherman as an example. Absent such frontstorage compartment, the driver would have to secure any objects to thefront or rear racks 110 or 124 by using ropes or the like. This is timeconsuming.

[0080] A plurality of additional storage containers or accessoriesadapted to be inserted into the open area 200 may be provided. Anexample of an additional storage container is illustrated in FIG. 15 andcomprises a container portion 200 and a hatch 202. FIG. 16 illustratesthe possibility of providing an additional fuel tank 204 that is securedto the vehicle via mounting brackets 206. Evidently, this type ofadditional fuel tank will have to respect all applicable security andliability requirements before being installed on the vehicle. Anotherpossible embodiment concerning a smaller tank 208 is shown in FIG. 17.

[0081] Other types of accessories, such as a winch 210, may also beprovided, preferably within the front portion of the vehicle underneaththe storage compartment 180.

[0082] The above description of a preferred embodiment should not beinterpreted in any limiting manner since variations and refinements arepossible which are within the spirit and scope of the present invention.The scope of the invention is defined in the appended claims and theirequivalents.

The embodiments of the invention for which an exclusive property orprivilege is claimed are defined as follows:
 1. A saddle-type vehiclecomprising a frame, a pair of front wheels suspended from a frontportion of said frame, a pair of rear wheels suspended from a rearportion of said frame, a power unit mounted on said frame, atransmission allowing said power unit to transmit power to either one ofsaid front or rear pairs of wheels, a seat located in between said frontand rear pairs of wheels, wherein a main portion of said power unit isdisposed beneath said seat.
 2. The vehicle of claim 1, wherein a mainportion of said transmission is also disposed beneath said seat.
 3. Thevehicle of claim 1, wherein said power unit comprises a crankshaft and atransmission shaft extending in a running direction of said vehicle, andwherein a rear drive shaft is connected to a rear end of saidtransmission shaft on one end and to a rear differential on the otherend to allow said power unit to transmit power to said pair of rearwheels.
 4. The vehicle of claim 3, further comprising a front driveshaft connected to a front end of said transmission shaft on one end andto a front differential on the other end to allow said power unit totransmit power to said pair of front wheels.
 5. The vehicle of claim 1,wherein said power is transmitted to either one of said front or rearpairs of wheels through a drive chain and sprocket arrangement.
 6. Thevehicle of claim 1, wherein said seat is pivotably connected to saidframe, said seat being moveable between a first position whereby thedriver may drive the vehicle and a second position whereby the drivermay access the power unit.
 7. The vehicle of claim 3, wherein said seatcomprises a pommel located at a front portion thereof.
 8. The vehicle ofclaim 1, wherein said seat is removably connected to said frame.
 9. Asaddle-type vehicle comprising a frame, a pair of front wheelscomprising first and second wheels suspended from a front portion ofsaid frame, a pair of rear wheels comprising third and fourth wheelssuspended from a rear portion of said frame, said first and secondwheels defining a first transversal axis and said third and fourthwheels defining a second transversal axis, a power unit mounted on saidframe, a transmission allowing said power unit to transmit power toeither one of said front or rear pairs of wheels, a seat located inbetween said front and rear pairs of wheels, wherein a main portion ofsaid power unit is located between said second transversal axis and animaginary axis located at a median point between said first and secondtransversal axis.
 10. The vehicle of claim 9, wherein said power unitcomprises a crankshaft and a transmission shaft extending in a runningdirection of said vehicle, and wherein a rear drive shaft is connectedto a rear end of said transmission shaft on one end and to a reardifferential on the other end to allow said power unit to transmit powerto said pair of rear wheels.
 11. The vehicle of claim 10, furthercomprising a front drive shaft connected to a front end of saidtransmission shaft on one end and to a front differential on the otherend to allow said power unit to transmit power to said pair of frontwheels.
 12. The vehicle of claim 9, wherein said power is transmitted toeither one of said front or rear pairs of wheels through a drive chainand sprocket arrangement.
 13. A saddle-type vehicle comprising a frame,a pair of front wheels suspended from a front portion of said frame, apair of rear wheels suspended from a rear portion of said frame, a powerunit mounted on said frame, a fuel tank, a transmission allowing saidpower unit to transmit power to either one of said front or rear pairsof wheels, a seat located in between said front and rear pairs ofwheels, wherein a main portion of said fuel tank is disposedsubstantially below the horizontal plane defined by the uppermostportion of said seat.
 14. The vehicle of claim 13, wherein a mainportion of said power unit is disposed beneath said seat.
 15. Thevehicle of claim 14, wherein a main portion of said transmission is alsodisposed beneath said seat.
 16. A saddle-type vehicle comprising aframe, a pair of front wheels suspended from a front portion of saidframe, a pair of rear wheels suspended from a rear portion of saidframe, a steering member connected to a steering mechanism for steeringsaid front wheels, a power unit mounted on said frame, a fuel tank, atransmission allowing said power unit to transmit power to either one ofsaid front or rear pairs of wheels, a seat located in between said frontand rear pairs of wheels, wherein a main portion of said fuel tank islocated beneath said steering member.
 17. The vehicle of claim 16,wherein a main portion of said fuel tank is also disposed substantiallybelow the horizontal plane defined by the uppermost portion of saidseat.
 18. The vehicle of claim 13 or 16, wherein said fuel tank isdisposed vertically.
 19. A saddle-type vehicle comprising a frame, apair of front wheels suspended from a front portion of said frame, apair of rear wheels suspended from a rear portion of said frame, asteering member connected to a steering mechanism for steering saidfront wheels, a seat located in between said front and rear pairs ofwheels, a power unit mounted on said frame and having a main portionthereof being disposed beneath said seat, a fuel tank located beneathsaid steering member, a transmission allowing said power unit totransmit power to either one of said front or rear pairs of wheels, saidvehicle further comprising an open area located between said fuel tankand said power unit, said open area providing easier access to and fromsaid vehicle.
 20. The vehicle of claim 19, comprising an additionalstorage container removably secured in said open area.
 21. The vehicleof claim 20, wherein said additional storage container is an additionalfuel tank.
 22. A saddle-type vehicle comprising a frame, a pair of frontwheels comprising first and second wheels suspended from a front portionof said frame, a pair of rear wheels comprising third and fourth wheelssuspended from a rear portion of said frame, a water cooled enginemounted on said frame, a transmission allowing said engine to transmitpower to either one of said front or rear pairs of wheels, a seatlocated in between said front and rear pairs of wheels, said vehiclefurther comprising a radiator located at said rear portion of saidframe.
 23. The vehicle of claim 22, wherein said radiator is locatedbetween said third and fourth wheels.
 24. The vehicle of claim 22,wherein said radiator is located behind said seat.
 25. The vehicle ofclaim 24, wherein said radiator is angled generally toward said seat.26. The vehicle of claim 22, wherein said radiator further comprises acooling fan disposed behind said radiator.
 27. The vehicle of claim 22,further comprising ventilation opening for conveying cooling air to saidradiator.
 28. The vehicle of claim 27, comprising at least two saidventilation openings located above said third and fourth wheelsrespectively.
 29. A saddle-type vehicle comprising a frame, a pair offront wheels suspended from a front portion of said frame, a pair ofrear wheels suspended from a rear portion of said frame, a steeringmember connected to a steering mechanism for steering said front wheels,a seat located in between said front and rear pairs of wheels, a powerunit mounted on said frame, a fuel tank, a transmission allowing saidpower unit to transmit power to either one of said front or rear pairsof wheels, said vehicle further comprising a storage compartment locatedforward of said steering member.
 30. A saddle-type vehicle comprising aframe, a pair of front wheels suspended from a front portion of saidframe, a pair of rear wheels suspended from a rear portion of saidframe, a steering member connected to a steering mechanism for steeringsaid front wheels, a seat located in between said front and rear pairsof wheels, a power unit mounted on said frame and having a main portionthereof being disposed beneath said seat, a fuel tank located beneathsaid steering member, a transmission allowing said power unit totransmit power to either one of said front or rear pairs of wheels, saidvehicle further comprising an open area located between said fuel tankand said power unit, said open area providing easier access to and fromsaid vehicle, said vehicle further comprising a storage compartmentlocated forward of said steering member.
 31. A saddle-type vehiclecomprising a frame, a pair of front wheels comprising first and secondwheels suspended from a front portion of said frame, a pair of rearwheels comprising third and fourth wheels suspended from a rear portionof said frame, said first and second wheels defining a first transversalaxis and said third and fourth wheels defining a second transversalaxis, a power unit mounted on said frame, a transmission allowing saidpower unit to transmit power to either one of said front or rear pairsof wheels, a seat located in between said front and rear pairs ofwheels, wherein a main portion of said power unit is located betweensaid second transversal axis and an imaginary axis located at a medianpoint between said first and second transversal axis, wherein a mainportion of said fuel tank extends generally vertically and is disposedsubstantially below the horizontal plane defined by the uppermostportion of said seat, said vehicle further comprising an open arealocated between said fuel tank and said power unit, said open areaproviding easier access to and from said vehicle.